Does it take as much energy to make somthing hot as it does to make it cold?

Question

e.g if room temperature is 20 deg c will it take the same amount of energy to reduce the temperature to 0 Deg c as it will to raise the temperature to 40 deg c ?

Answer 1

It depends on what you mean by "energy".

In an idealized thermodynamic system in which both rooms are completely isolated from the outside world (no heating or cooling from the outside), then you would add exactly as much energy to the room to raise its temperature by 20 degrees as you would take out to reduce its temperature by 20 degrees.

Rooms are generally NOT idealized systems and are in contact with the outside world, which will help provide (or remove) energy necessary to keep the room at the outside temperature. Let's assume, for argument's sake, that the outside temp is 20 degrees, so the outside has the same effect in both cases.

If you are asking about "energy" as "what we buy from'the power company", then your REAL question is , what is more efficient - heating or cooling a room? The answer depends on the way we choose to heat and cool rooms. With either process there is wasted energy.

A good heater is generally more energy efficient than a good air conditioner, which is one reason why it is a bigger problem when New York City has a week of 100 degree F weather, as oppossed to a week of 40 degree F weather (for non-Americans, the ambient temperature is 70 degrees F).

In summary, the amount of energy that goes into raising or lowering the temperature is excactly the same. BUT, it would require more energy per second, or power, to cool the room than it would to heat it only because of the current technology and energy sources. Heaters are more efficient than air conditioners currently are . Power is what you pay for at the end of the month (in BTUs or KWHs).

Good question!

Answer 2

in cooling the air, it is necessary to remove the energy out of the system. When your heating the air, it is necessary to add energy into the system. Both will require the same amount of energy to make it change by the same amount of temperature change. However, the most efficient thing is to heat the air rather than cooling it when it comes to practical methods. A heater is more efficient than a refrigerant system. With this in mind it would take more energy to cool the air down due to enneficiencies!

Answer 3

Think of the huge amount of energy required to cool anything to absolute zero (assuming this could be done) and compare that with the energy required to heat the same anything to 279 deg (hope that's the correct figure!)

Answer 4

Yes.

Forget man, forget man-made devices. We have the sun, my friend, an energy source that will serve our purpose.

Assumptions:
- no volcanic eruptions
- the sun produces a constant amount of energy over one year

An object on the earth is at 20°C
Some times, depending on the weather and the season, the object warms up to 40°C.
Other times, the object cools down to 0°C.

The only useful energy source now being the sun, then it takes as much energy to warm up the object by 20°C than it takes to cool it down by 20°C, because there is only one constant energy source.

Q.E.D.

Answer 5

Given that the formulae for calculating Kcalories and BTUs work both ways, for heating and cooling, you might think that they were the same, but you have to take into account the ambient temperature, which would normally be above 0C. In which case cooling would normally take longer. There are also lots of other parameters to be taken into account such as the materials involved, air pressure, method of heating/cooling etc.

Answer 6

It takes more energy to heat something than to cool something because a lot of things cool in room temperature.

Answer 7

Decreasing temperature is the loss of energy just as during heating the object up was it gaining energy.

Answer 8

cooling is easier

This is because the monocles are more spread out when warm therefor it is easier to cool than it is to warm it up so is takes less energy to cool down to 0 than it is to warm to 40

Answer 9

likely takes more energy to make it cold

Answer 10

Yes is the short answer....